1. Technical Field
The present invention is directed toward window operators, and more particularly toward window operators:adapted to opening and closing of a window sash relative to a window frame.
2. Background Art
There are, of course, any number of different types of window (and other closure) operators which are well known in the art. Examples of such operators are shown, for example, in Van Klompenburg U.S. Pat. No. 4,136,578, Van Klompenburg et al. U.S. Pat. No. 4,241,541, Peterson et al. U.S. Pat. No. 4,253,276, Erdman et al. U.S. Pat. No. 4,266,371, Nelson U.S. Pat. No. 4,305,228, Sandberg U.S. Pat. No. 4,346,372, Vetter U.S. Pat. No. 4,497,135, Tacheny et al. U.S. Pat. No. 4,521,993, Vetter U.S. Pat. No. 4,617,758, Allen U.S. Pat. No. 4,823,508, Tucker U.S. Pat. No. 4,840,075, Nolte et al. U.S. Pat. No. 4,843,703, Nolte et al. U.S. Pat. No. 4,845,830, Tucker U.S. Pat. No. 4,894,902, Tucker et al. U.S. Pat. No. 4,937,976, Nolte et al. U.S. Pat. No. 4,938,086, Berner et al. U.S. Pat. No. 4,945,678, Tucker et al. U.S. Pat. No. 5,054,239, Tucker et al. U.S. Pat. No. 5,152,103, and Vetter et al. U.S. Pat. No. 5,199,216.
Generally speaking, such operators have used a variety of linkages in combination with suitable hinge structures, where the operator linkages are actuated by rotation of a manual or powered drive connected to the linkage through assorted worm gear drives.
It is a basic requirement of all such operators that they be able to withstand the extremely high loads often encountered such as, for example, when breaking the weatherstrip seal during initial opening of the sash and when closing the window sash to seal about the entire periphery of the weather strip. Further, operational and aesthetic requirements relating to the orientation of different parts of the drive train of the operator have necessitated the use of high strength, and relatively costly, materials (such as suitably hardened metals). Such materials are inherently susceptible to corrosive environments such as are commonly found in many areas, particularly in seaside dwellings. In order to provide a long useful life for the operator, various attempts have been made to coat or treat the metal components to resist corrosion. However, even the most successful of such treatments can significantly increase the cost of manufacturing the operator.
The present invention is directed toward overcoming one or more of the problems set forth above.